The present application relates to nanoparticles, and more particularly to metallic nanoparticle suspensions that are stable in buffered aqueous solution and are also chemically reactive under normal temperatures and conditions.
Note that the points discussed below may reflect the hindsight gained from the disclosed inventions, and are not necessarily admitted to be prior art.
Metallic nanoparticles display fascinating properties that are quite different from those of individual atoms, surfaces or bulk materials. Applications, or potential applications, are diverse and interdisciplinary. They include, for example, use in biochemistry, in catalysis and as chemical and biological sensors, in medicine. The properties of the metallic nanoparticles can vary depending on whether they are free, deposited on a surface or embedded in a matrix of another material.
Due to their characteristic easy-to-measure physical properties and chemically inertness, metallic nanoparticles have been used in the fabrication of targeted probes for bioagent detections and separations. Targeted bioagents can include bio-organisms such as virus and bacteria, or bio-molecules such as antigens, antibodies, proteins, nucleic acid, peptides, hormones as well as bioactive small molecules. Probe-attached nanoparticles are used also in vivo to recognize and locate specific ligands in specific tissues or organs.
In order to detect bioagents, target specific ligands, such as antibodies or nucleic acid, need to be attached to the surface of nanoparticles.
Traditionally, targeted specific ligands, such as antibodies, nucleic acid, proteins or peptides were absorbed to the surface of nanoparticles via static, non-specific interactions. The optimal binding conditions depend on many factors including salt concentration, buffer type, pH and stabilizing agents. These methods are tedious, laborsome and time consuming. Nanoparticle probes generated from these methods usually suffer poor stability and the attached probes can easily become detached from the metal nanoparticles.